Add all required dependencies for backend

requirements.txt

@@ -6,7 +6,7 @@ python-dotenv==1.0.1
 # --- LangChain stack (old structure compatible with your retriever) ---
 langchain==0.1.16
 langchain-community==0.0.32
-langchain-groq==0.0.2
+langchain-groq==0.1.0
 sentence-transformers==2.2.2
 faiss-cpu==1.7.4
 tiktoken==0.7.0